Isnt there a caveat that all wives should be treated equally and there should be no favourites.

I was joking there ... Actually the thought that had occurred to me was how a person would manage with multiple spouses. The logistics of it. If you were a king in the olden days, no problem then, but in this day and age, it can get real tough. AFAIK, the number of polygamous families is low in India, even among Muslims, who legally can have multiple wives.